Quickset Speed Question

DCS engines accelerate and decelerate base on the setting(s)/rates that are set(programed) into the remote for each individual engine.

That's what I thought, but I put in a 2mph setting, and they take off and immediately race to the new set speed.

 I prefer the #1 setting on both. Seems to give the best. Wish it was more adjustable as previously discussed at the meetings.

John that does not sound right.  Set at 2 smph/sec it should take 5 seconds for any and each 10 smph change.

Does this engine respond to normal thumbwheel changes?  Is this a new engine?  PS-2 or PS-3?

This is pretty universal with all the PS/2 stuff I have.  I thought it should work differently.

I have set 1mph for ACC and DEC in control.  The locomotive is stopped.  I do a Quickset to 30 MPH.  In my thinking, it should take 30 seconds to get to full speed, and 30 seconds to stop.  It takes roughly 6 seconds for each operation, getting to speed and stopping.

I don't see any other obvious adjustment that could explain this.  Since it's not just one locomotive, this has to be some other configuration that I'm unaware of.

I tried this with a 5V PS/2 steamer and a 3V PS/2 diesel, exactly the same reaction and response.  It happens in the same amount of time too, about 6 seconds instead of 30 for 30 MPH.

Agreed that it is pretty universal and I also thought it should work differently.   All of my PS2 and PS3 engines ramp up pretty quickly even when acceleration rate is set to "1".  

Aren't ACC and DEC accelerations rates, not velocities?  Shouldn't it be SM/H/H ?

Well, that's what I thought they were.  If I accelerate from 0 MPH to 30 MPH and have a ACC rate of 1, shouldn't it take 30 seconds to get up to 30 MPH?  The same when going from 30 MPH to 0 MPH, at a DEC setting of 1, I'd expect it to ramp down and take 30 seconds to stop. 

Am I using these all wrong?  I'm willing to learn.

Velocity by deffinition requires TWO components that is SPEED and DIRECTION.  Velocity is a Vector measurement/quantity.

Acceleration + or - is just a rate of change in speed.

And yes if the ACC rate is set at 1 then it should take 30-seconds to go from 0 to 30 smph.   Barry explains this in his book Appendix F.  I thought by now he would join in on this discussion.

Unfortunately all my engines are packed away now.  But I am expecting a new within a week or so and will check this feature out when testing at the dealers before actual purchase.

That was my feeling, it shouldn't be any more complicated than that.  I've tried three different PS/2 locomotives, including one that I just installed the PS/2 upgrade kit into, all don't seem to obey the acceleration configuration.  I did look up the features, and I don't see that I should have to do anything else to make this work.

I point out that this is dirt simple on my Legacy system, just punch the right button.

Guys,

Yes, the book's definition is essentially correct. However, it's been a while since I wrote that section. When I have a chance, I'll stopwatch an engine and see how it behaves in "the real world".  

I point out that this is dirt simple on my Legacy system, just punch the right button

Simple, yes. Accurate, hardly.

Legacy's completely missing any frame of reference, since Legacy engines do not have consistent speed step increments across all Legacy engines, and Legacy speed steps are not calibrated in miles per hour, scale or otherwise. When a Legacy engine accelerates or decelerates, one has no idea of what is the rate of acceleration or deceleration.

Well, I just did the experiment with three different engines, trying to use a variety of PS/2 boards and sound files.

The preliminary conclusion?  The acceleration and deceleration controls have a consistent behavior, just not accurate.

I set the ACC and DEC to one on each of the locomotives.  Every one of them seem to operate about 4:1 acceleration, i.e. when I either accelerate from 0 to 50 or decelerate from 50 to 0, it takes about 12 seconds.  That's consistent for all three locomotives.

I don't see anything else I can set to make this work properly, it's the same for diesels as steamers.

While Legacy isn't "accurate", at least I can get very slow acceleration that's more prototypical, which is what I was shooting for.

I've had it confirmed by yet another source, so apparently this is another bug they can fix in the next version of software.

I'm presuming that the ramp up is controlled from the TIU and not done in the locomotive directly.

Another question comes to mind. 

With the Legacy controller I can have up to five engines accelerating slowly to a set speed.  Presuming the acceleration ever gets properly corrected, can you have more than one locomotive accelerating at once, controlled with one remote?

John,

can you have more than one locomotive accelerating at once, controlled with one remote?

Yes, as many as you like, using one or several remotes.

Well, now if they'd only fix the acceleration so it actually matched the settings, it would be great!

I have the same "issues", actually I think the BOOST and BRAKE toggle works better, or at least the way I would like to see the ACC/DEC perform.

Bob, it's becoming apparent that the setting for acceleration and deceleration are just eye candy, they don't actually work that way.   They are relative, if you set them to bigger numbers, they react even quicker.  However, the real utility would be if they acted slower.

John,

Here's what the DCS manual says on page 53 about the ACC and DEC rates:

ACC RATE:

The “Boost” button on the remote boosts
your locomotive’s speed at the rate set
here.

DEC RATE:

The “Brake” button on the remote slows
your locomotive’s speed at the rate set
here.

So hitting the Boost button increases the speed of the engine according to what the acceleration rate was set to and the Brake button decreases the speed of the engine according to what the deceleration rate was set to.

On page 78 it talks about the Quick Set Speed:

1. Press MENU
2. Select SYSTEM
3. Select REMOTE SETUP
4. Select QUICKSET SPEED
5. Select ON or OFF
6. When ON is selected you are able to
send any speed you want to an engine
quickly.
7. Press the ENG button and then select
a DCS-equipped engine from the list.
8. Press down on the thumbwheel (Select)
and you will see the display change to
indicate “QUICKSET SPEED”.
9. Using the numeric keypad enter the
speed you want that engine to go.
10. Press the thumbwheel down again
(Select) and you will see your engine
moving at the speed you selected.

Maybe I haven't been turning it ON to start with , but I don't see where it says anything about the Quick Set Speed being tied to the ACC/DEC rates.

Time to check it out!

You could be right Bob.  It sure seems logical that the Quickset should use the acceleration value, and since the acceleration value does affect the speed that Quickset attains the set speed, it's clear that they're looking at the acceleration value.  The fact that those values do affect Quickset seems to indicate they intended it to work that way, and it's certainly what most folks would probably desire. 

Also, note that the manual says:

When ON is selected you are able to send any speed you want to an engine quickly

That's exactly what I want to do, send the speed to the locomotive.  However, I don't want it to jackrabbit to the speed.   If I need jackrabbit, I can set the acceleration values up to a nice high value.

It would be nice to get clarification from MTH as to exactly what is supposed to happen, but I'll bet they'll just say it's "working as designed".

However, I don't want it to jackrabbit to the speed.

Exactly

I'd like to start my train coming out of the yard at "yard speed" then let it S-L-O-W-L-Y attain the speed I want it to run on the mainline.  1mph every 5 seconds would be nice.  So going from 10mph to 28mph (18mph increase) would take (18x5) 90 seconds.

Gosh Bob, I'd be happy if it would accelerate at 1MPH/second as the settings seem to allude to.

John,

I just pulled that out of my......., I have no idea what a REAL engine could do (maybe someone can tell us).

I know the N&W "J" 611 could move out, I saw it hit a pretty good speed as it past me and my dad coming from the N&W bridge #7 (milepost 6.6) at Gilmerton to Yadkin Road (milepost 10.5) the day it wrecked in the Dismal Swamp, back in 1986.  Mr. Claytor had that beast really moving.

I'm guessing the real locomotive would be limited by the size of the consist.  If they had a few empty cars, probably pretty impressive acceleration.  However, a 70 loaded car consist would probably accelerate a lot slower.

I kind of like the brake feature, It's been a while since I've tried it but it somewhat prototipical correct, heavy  trains take a while to slow down.( I know there are some setting that will retain the slower speed after using the brake feature ) but  after using the brake and releasing it the train  speeds up way tooo fast. gunrunnerjohn has it right. It takes a while to get a heavy train back to track speed  after using the train brake.

Quikset speed does not use any acceleration or deceleration settings   Its to quickly get to the speed desired. If you set it to 25 its going to take off down the track until it reaches 25 quickly.  If you want acceleration or deceleration rates you have to roll the thumbwheel and not use quikset spreed

That's also the way I thought it worked.  I turned the feature off because I didn't see any real advantage to using it.

According to my experiments Ben, that would not be totally correct.  If you change the acceleration figures to something high, say 20, the locomotive will accelerate a lot faster than when the acceleration figure is at 1, try it and see.  They seem to be looking at the acceleration figure.

I've been following this interesting discussion.

Where I notice the single biggest difference is when setting the DEC rate.  If I hit DIR button with a DEC of 10, the train stops virtually instantly (which I like).  If I set DEC to '1' the train drifts a ways after hitting DIR.  Since I have lots of kids running trains on my layout I set it to 10.

I don't see any difference in changing the ACC rate, but then I typically don't use Brake and Boost.

- walt

I was specifically measuring the braking time, since that was the easiest to check.  Get the train running and then do a Quickset 0 and time it.  It was slower accelerating with lower acceleration values as well, but it's a bit harder to determine when it's reached the set speed.

Since they appear to be using the acceleration/deceleration value for some part of the Quickset calculation, why not use it correctly?

A question occurs. 

I've been assuming that the ramping is done in the remote or TIU, and the locomotive would simply be responding to the commands.  Is that correct?  Maybe I'm coloring the test with my selection of test engines.

OK, took a completely different locomotive, an older 5V PS/2 diesel. I wanted to eliminate any issues that might be happening with the other two I was testing with.

The acceleration and deceleration settings most definitely affect both acceleration and deceleration using QuickSet.  When I set them both to 20, the effect is basically instant for either increasing or decreasing speed.  When I set them both to 1, I get a rate of roughly 4-5 MPH change a second for increasing or decreasing speed.

As mentioned in the thread, the boost and brake operate slower, but again not actually as described.  I get 35 seconds to slow from 50 MPH to stopped using the brake function.  Using a boost of exactly 30 seconds from stopped, I get 45 MPH.

Bottom line is the actual values in the acceleration and deceleration settings don't faithfully correspond to anything, but they're a general indication of how fast you'll accelerate or decelerate to a speed using either of the two methods described.

Although the boost and brake gets closer to the slow acceleration, they have a major shortcoming for many folks.  They require dedicated attention of the remote to the single engine, where if QuickSet were to function in a similar manner, you could set an acceleration for an engine and move on.  That's what I was trying to do when I started chasing all this down.

I have never been able to makes sense of DCS acceleration/deceleration rate. Especially the acceleration, it is way too fast for my liking. Makes it hard sometimes to run DCS and Legacy together. 

That's it exactly Jeff.  I can get two or three Legacy (or TMCC) locomotives slowly ramping up their speed at the same time using high momentum, works great.  However, for DCS, the only method is using QuickSet, and that's simply too "quick".   If I used the boost, which is closer to the behavior I'd like, I'm stuck holding the key until the locomotive gets to speed, and I can't do anything else with the remote.